Self-oscillating flow field inside the nozzle chamber variation, internal and external flow field dynamic pressure variation

Abrasive jet formation mechanism of the pulse, the pulse characteristics and pulsed abrasive water jet abrasive jet perforating stimulation mechanism and other issues have been studied, and in the Sichuan Basin, a gas well site experiments. The main  polycrystalline diamond : first using a large eddy simulation, through in-depth analysis of the self-oscillating flow field inside the nozzle chamber variation, internal and  synthetic diamond  field dynamic pressure variation, variation of the velocity vector, turbulence intensity distribution, revealing the self-oscillating  abrasive wheels  jet generation mechanism; combined oscillation, bubble collapse on the abrasive jet impact and solid abrasive water jet in the pulse distribution of abrasive water jet pulses revealed the formation mechanism.

Using perforating fracturing methods to transform strata, increased gas production

Low-permeability gas widely distributed in China, large reserves, proven gas reservoirs representing more than 80%. However, due to porosity, permeability and pressure is low,  polycrystalline diamond low productivity and economic inefficiency. In order to increase natural gas production, to solve the "gas shortage" problem, now mostly using perforating fracturing methods to transform formation, increased  Diamond blade . However, the conventional way of perforation perforation shallow depth, hole diameter is small, the construction for a long time, can lead to gas  Synthetic diamond , resulting in low permeability gas reservoirs, yield poor. For these reasons, this paper proposes a pulsed abrasive water jet perforation penetration increased permeability gas reservoir to increase natural gas production of new ideas.

In submerged conditions before and after mixing abrasive jet impact angle, flow, pressure

Using FLUENT software, submerged abrasive jet multiphase flow simulation, calculation of different structural forms of the nozzle flow field inside and outside. Explored the submerged condition after mixing abrasive jet impact angle, flow, pressure, target distance, sand tube length, tube diameter mixed sand, abrasive concentration,  synthetic diamond  change on the nozzle flow field inside and outside the law, on the abrasive particles running track were predicted, while the flow field  polycrystalline diamond  and calculation results are analyzed. For premixed abrasive water jet, respectively, direct numerical simulation of 260,450,600 cone type nozzle and external flow field and grain motion characteristics, and submerged jet  abrasive grinding  under influence factors - target distance, angle of impact and confining pressure for the simulation analysis. The results showed that: there is a submerged abrasive jet jet core, is about (35) D, but then jet decay rapidly. Cylinder, cone, cone straight three typical straight-type nozzle nozzle cone best, and to 260 straight cone nozzle effect is better.

Water by adding abrasives (ie, abrasive water jet) is to improve the performance of an important way jet

For higher pressure jet working condition, basically limited to some of the research sector from abroad pressure generator and jet equipment research work. Attempts have been made in the high-pressure water jet technology, and continue beyond the new high record Generally said current level of technology enables people to use 200 ~ 400 MPa  synthetic diamond  while with further increase the pressure in the device and the device manufacturing, material, cost and other aspects of life will be limited, there is also the use of security .70 years, people began to note exhausted improve the work efficiency of the jet, focusing on research work  synthetic diamond powder  not too high but with a high-performance jet mechanism, for example, additives jet, 'pulse jet, resonance jet, jet and abrasive water jet cavitation in an attempt to lower operating pressure, achieve a higher economic  cutting tools , added to the water abrasive (ie, abrasive water jet) is to improve the performance of a jet important way. abrasive jet high pressure water jet and general different, it is a highly concentrated jet of energy, the working medium is water and a mixed solution of abrasive particles.

Explained rotating abrasive jet nozzle jet nozzle wear serious than ordinary phenomenon

Comparison of the rotating abrasive jet nozzle and the general stress abrasive jet nozzle, the results showed that: the former is much larger than the maximum stress in the latter, which could well explain the rotating  Polycrystalline diamond  nozzle jet nozzle wear serious than  abrasive grinding . Study of the various parameters of the law of the nozzle wear, these parameters were as follows: the abrasive characteristics (shape abrasive,  Diamond blade  size, grain hardness, abrasive concentration), nozzle material properties and surface quality (hardness nozzle, abrasive hardness H_α and nozzle material hardness H_m ratio nozzle processing quality), nozzle structural parameters (inlet contraction angle, nozzle diameter), the jet operating parameters.

Erosion in the nozzle inlet end face wear play a major role

From the nozzle wear mechanisms and effects of two parts for rotary drilling abrasive jet conducted exploratory research. Through  polycrystalline diamond  analysis, the rotating abrasive jet nozzle wear plays a decisive role in the abrasive wear and erosion. Where  cutting tools  is the main form of the nozzle inner wear, and erosion in the nozzle inlet end face wear plays a major role, and were the two wear mechanisms were discussed.  synthetic diamond  method analysis of the stress state in the nozzle. The results showed that: the maximum stress in the nozzle cone section at the beginning of the end of the straight section, the stress cone section is smaller and showed an increasing trend, the average stress is greater than the straight section cone section, in addition to the entrance face of stress as well.

Rotating water jet diffusion angle measured experimental analysis of all relevant parameters on the jet spread angle of the law

Combined rotary abrasive jet casing window casing window mechanism and a set of practical requirements designed impeller, nozzle suitable for indoor as well as experimental research tools, and its strength check. Checking results show that the designed tools to meet the requirements. By  abrasive wheels  jet diffusion angle measured  synthetic diamond  analysis of all relevant parameters on the jet spread angle is studied. The experimental results showed that: rotating water jet pump is larger in the diffusion angle does not vary with the pump pressure is changed, the proliferation of  cutting tools  with water jet nozzle diameter, the impeller blade outlet angle and the number increases. By rotating the casing window abrasive jet experimental analysis of all relevant parameters on the effect of regular windows and preferably out of the relevant parameters.